Suggestion to Astronauts: Look, Ma, No Hands

It was evaluation time at Cape Canaveral last week, and if U.S. space technicians have any complaint, it is that U.S. space travelers still seem to think they are primarily airplane drivers. Like Colonel John Glenn before him, Commander Scott Carpenter soared into orbit with remarkably little faith in his capsule's automatic positioning equipment. He spent all but a few minutes of his five hours aloft "flying" his spaceship by hand, changing its attitude while in orbit with squirts of peroxide steam, at one point using two systems at once. As a result, he all but ran out of fuel, almost fouled up the delicate business of re-entry into the earth's atmosphere (TIME, June 1). Even so, he managed to keep remarkably busy at other things; he completed a surprising number of experiments designed to help future astronauts to study the tricks and tribulations they will have to handle as man races toward the moon.

No More Stars. Above Carpenter's right ear hung a glass globe in which he studied the movements of fluids freed from gravity. He had a camera with which he took pictures through the window, using several filters. He experimented with eating new kinds of special space food. He measured the brightness of stars and other outside objects with a photometer. Intricate gadgetry demanding his attention was everywhere. But for all his preoccupations, the astronaut found time to take a careful, searching look at the earth below him. And he brought back the best report yet of how man's home looks from nearby space. The sky is velvety black, he said, and against it the sunlit earth glows in brilliant shades of blue and green--colors hard to imagine or duplicate because of their wonderful purity. Everywhere the earth is flecked with white clouds. When his capsule swept over the dark side of the earth, the ground was lit only by the feeble glow of the quarter-moon. But he could still see the horizon against the deeper black of the sky, and point his capsule by it.

All orbiting astronauts, starting with Yuri Gagarin, saw a bright blue band around the earth. Carpenter looked more carefully through a special filter and saw two bands, the lower one made up of many colors--red, blue, white and a little green. The pictures that he took of the two bands are being analyzed at M.I.T., where they are considered important for the design of instruments to sense the edge of the earth and guide the return of home-bound future spaceships.

When he turned his attention upward and outward--away from earth and toward the vast reaches of space--Carpenter discovered that the interiors of future spaceships will have to be redesigned if passengers are to get a clear look at the starry sky. Since he had to keep watching his instruments, Carpenter could not turn off Aurora 7's panel lights, so his eyes never became adapted to darkness; he saw no more stars than are visible from earth. He did not see the Gegenschein, a comet-like trail of particles that is believed to follow the earth.

Closer in to his capsule, though, Carpenter did solve a mystery: he satisfied himself that he had identified the glowing, drifting objects that intrigued both Glenn and Soviet Cosmonaut Titov. Space fireflies, Carpenter concluded, are only particles (presumably flecks of paint) from the capsule's skin. He proved the point by producing flocks of bright floating specks every time he rapped hard on his capsule's wall.

Too Much Control. By his own time-consuming efforts to control his capsule, articulate Astronaut Carpenter learned valuable lessons about how to fly, and how not to fly, orbiting spacecraft. Such a ship moves on a predetermined orbit, and except for firing retrorockets for reentry, an astronaut cannot appreciably change its course or speed. If he applies no control at all, the capsule will go through a drifting motion, rolling and tumbling slowly as it circles the earth.

But Mercury spacemen are tempted by three separate systems for controlling their capsules--manual, automatic and fly-by-wire. The manual system has direct mechanical connections between the control stick and the valves of a set of peroxide jets. When the astronaut moves the stick, steam blasts through selected jets to give the capsule the desired turning motion. Once it starts turning in frictionless space, it continues to turn, and it cannot be stopped without using more peroxide. Vigorous use of the manual system will quickly empty its fuel tank.

Slower but more economical of fuel, the automatic control system keeps the capsule's attitude steady without pilot attention. It has infrared horizon scanners that watch the boundary between the earth's warm curve and the cold sky and use this information to correct a set of gyroscopes. The gyros in turn control a set of jets, shooting small spurts of peroxide through them whenever necessary. If the capsule has been turned away from the horizontal attitude, the busy little scanners and gyros will turn it back again at 8DEG per minute. This is fast enough to keep it pointed properly, but too slow for smart, airplanelike maneuvers.

The third system at the astronaut's disposal, fly-by-wire, uses the jets and fuel supply of the automatic system, but is controlled by the hand stick. Instead of opening the peroxide valves directly, fly-by-wire works them through a set of electrical actuators. It is faster than automatic and smoother than manual control, but if it is used impatiently, it quickly drains the fuel of the automatic system.

Future spacecraft designed to cruise to the moon or Mars will have even more complicated control systems, on-course propulsion that can be turned on and off, and telescopes to track the earth, the sun and the target. If they intend to rendezvous with other spacecraft, they will probably carry radars for judging distances and intricate devices to bring the two ships together. But when their assured, experienced captains guide them into the velvet blackness, they will be using manuals based on the flights--and the mistakes--of such early pioneers as Glenn and Carpenter.

This file is automatically generated by a robot program, so reader's discretion is required.